polypath asymmetric routing: Handle MSG2-4 late dupes
[secnet] / site.c
CommitLineData
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1/* site.c - manage communication with a remote network site */
2
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3/*
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
6 *
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9c6a8729 9 * the Free Software Foundation; either version 3 of the License, or
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10 * (at your option) any later version.
11 *
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
20 */
21
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22/* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
30
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31/* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
34
8689b3a9 35#include "secnet.h"
2fe58dfd 36#include <stdio.h>
469fd1d9 37#include <string.h>
fe5e9cc4 38#include <limits.h>
58650a70 39#include <assert.h>
8689b3a9 40#include <sys/socket.h>
2fe58dfd 41
8689b3a9 42#include <sys/mman.h>
2fe58dfd 43#include "util.h"
59635212 44#include "unaligned.h"
ff05a229 45#include "magic.h"
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46
47#define SETUP_BUFFER_LEN 2048
48
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49#define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
50#define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
2fe58dfd 51#define DEFAULT_SETUP_RETRIES 5
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52#define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
53#define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
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54
55#define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
56#define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
57#define DEFAULT_MOBILE_SETUP_RETRIES 30
58#define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
59#define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
60
446353cd 61#define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
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62
63/* Each site can be in one of several possible states. */
64
65/* States:
66 SITE_STOP - nothing is allowed to happen; tunnel is down;
67 all session keys have been erased
68 -> SITE_RUN upon external instruction
69 SITE_RUN - site up, maybe with valid key
70 -> SITE_RESOLVE upon outgoing packet and no valid key
71 we start name resolution for the other end of the tunnel
72 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
73 we send an appropriate message 2
74 SITE_RESOLVE - waiting for name resolution
75 -> SITE_SENTMSG1 upon successful resolution
76 we send an appropriate message 1
77 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
78 we abort resolution and
79 -> SITE_WAIT on timeout or resolution failure
80 SITE_SENTMSG1
81 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
82 -> SITE_SENTMSG3 upon valid incoming message 2
83 -> SITE_WAIT on timeout
84 SITE_SENTMSG2
85 -> SITE_SENTMSG4 upon valid incoming message 3
86 -> SITE_WAIT on timeout
87 SITE_SENTMSG3
88 -> SITE_SENTMSG5 upon valid incoming message 4
89 -> SITE_WAIT on timeout
90 SITE_SENTMSG4
91 -> SITE_RUN upon valid incoming message 5
92 -> SITE_WAIT on timeout
93 SITE_SENTMSG5
94 -> SITE_RUN upon valid incoming message 6
95 -> SITE_WAIT on timeout
96 SITE_WAIT - failed to establish key; do nothing for a while
97 -> SITE_RUN on timeout
98 */
99
100#define SITE_STOP 0
101#define SITE_RUN 1
102#define SITE_RESOLVE 2
103#define SITE_SENTMSG1 3
104#define SITE_SENTMSG2 4
105#define SITE_SENTMSG3 5
106#define SITE_SENTMSG4 6
107#define SITE_SENTMSG5 7
108#define SITE_WAIT 8
109
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110int32_t site_max_start_pad = 4*4;
111
fe5e9cc4 112static cstring_t state_name(uint32_t state)
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113{
114 switch (state) {
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115 case 0: return "STOP";
116 case 1: return "RUN";
117 case 2: return "RESOLVE";
118 case 3: return "SENTMSG1";
119 case 4: return "SENTMSG2";
120 case 5: return "SENTMSG3";
121 case 6: return "SENTMSG4";
122 case 7: return "SENTMSG5";
123 case 8: return "WAIT";
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124 default: return "*bad state*";
125 }
126}
127
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128#define NONCELEN 8
129
130#define LOG_UNEXPECTED 0x00000001
131#define LOG_SETUP_INIT 0x00000002
132#define LOG_SETUP_TIMEOUT 0x00000004
133#define LOG_ACTIVATE_KEY 0x00000008
134#define LOG_TIMEOUT_KEY 0x00000010
9d3a4132 135#define LOG_SEC 0x00000020
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136#define LOG_STATE 0x00000040
137#define LOG_DROP 0x00000080
138#define LOG_DUMP 0x00000100
139#define LOG_ERROR 0x00000400
446353cd 140#define LOG_PEER_ADDRS 0x00000800
2fe58dfd 141
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142static struct flagstr log_event_table[]={
143 { "unexpected", LOG_UNEXPECTED },
144 { "setup-init", LOG_SETUP_INIT },
145 { "setup-timeout", LOG_SETUP_TIMEOUT },
146 { "activate-key", LOG_ACTIVATE_KEY },
147 { "timeout-key", LOG_TIMEOUT_KEY },
148 { "security", LOG_SEC },
149 { "state-change", LOG_STATE },
150 { "packet-drop", LOG_DROP },
151 { "dump-packets", LOG_DUMP },
152 { "errors", LOG_ERROR },
446353cd 153 { "peer-addrs", LOG_PEER_ADDRS },
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154 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
155 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
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156 { "all", 0xffffffff },
157 { NULL, 0 }
158};
159
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160
161/***** TRANSPORT PEERS declarations *****/
162
163/* Details of "mobile peer" semantics:
f6eff504 164
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165 - We use the same data structure for the different configurations,
166 but manage it with different algorithms.
446353cd 167
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168 - We record up to mobile_peers_max peer address/port numbers
169 ("peers") for key setup, and separately up to mobile_peers_max
170 for data transfer.
171
172 - In general, we make a new set of addrs (see below) when we start
173 a new key exchange; the key setup addrs become the data transport
174 addrs when key setup complets.
175
176 If our peer is mobile:
177
178 - We send to all recent addresses of incoming packets, plus
179 initially all configured addresses (which we also expire).
180
181 - So, we record addrs of good incoming packets, as follows:
182 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
183 2. add the peer of the just received packet to the applicable list
184 (possibly evicting the oldest entries to make room)
185 NB that we do not expire peers until an incoming packet arrives.
446353cd 186
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187 - If the peer has a configured address or name, we record them the
188 same way, but only as a result of our own initiation of key
189 setup. (We might evict some incoming packet addrs to make room.)
446353cd 190
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191 - The default number of addrs to keep is 3, or 4 if we have a
192 configured name or address. That's space for two configured
193 addresses (one IPv6 and one IPv4), plus two received addresses.
194
195 - Outgoing packets are sent to every recorded address in the
196 applicable list. Any unsupported[1] addresses are deleted from
197 the list right away. (This should only happen to configured
198 addresses, of course, but there is no need to check that.)
199
200 - When we successfully complete a key setup, we merge the key setup
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201 peers into the data transfer peers.
202
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203 [1] An unsupported address is one for whose AF we don't have a
204 socket (perhaps because we got EAFNOSUPPORT or some such) or for
205 which sendto gives ENETUNREACH.
206
207 If neither end is mobile:
208
209 - When peer initiated the key exchange, we use the incoming packet
210 address.
211
212 - When we initiate the key exchange, we try configured addresses
213 until we get one which isn't unsupported then fixate on that.
214
215 - When we complete a key setup, we replace the data transport peers
216 with those from the key setup.
446353cd 217
f6eff504 218 If we are mobile:
446353cd 219
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220 - We can't tell when local network setup changes so we can't cache
221 the unsupported addrs and completely remove the spurious calls to
222 sendto, but we can optimise things a bit by deprioritising addrs
223 which seem to be unsupported.
446353cd 224
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225 - Use only configured addresses. (Except, that if our peer
226 initiated a key exchange we use the incoming packet address until
227 our name resolution completes.)
446353cd 228
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229 - When we send a packet, try each address in turn; if addr
230 supported, put that address to the end of the list for future
231 packets, and go onto the next address.
446353cd 232
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233 - When we complete a key setup, we replace the data transport peers
234 with those from the key setup.
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235
236 */
237
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238typedef struct {
239 struct timeval last;
240 struct comm_addr addr;
241} transport_peer;
242
243typedef struct {
244/* configuration information */
245/* runtime information */
246 int npeers;
0f27325c 247 transport_peer peers[MAX_PEER_ADDRS];
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248} transport_peers;
249
8b21a212 250/* Basic operations on transport peer address sets */
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251static void transport_peers_clear(struct site *st, transport_peers *peers);
252static int transport_peers_valid(transport_peers *peers);
253static void transport_peers_copy(struct site *st, transport_peers *dst,
254 const transport_peers *src);
255
8b21a212 256/* Record address of incoming setup packet; resp. data packet. */
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257static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
258static void transport_data_msgok(struct site *st, const struct comm_addr *a);
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259
260/* Initialise the setup addresses. Called before we send the first
261 * packet in a key exchange. If we are the initiator, as a result of
262 * resolve completing (or being determined not to be relevant) or an
263 * incoming PROD; if we are the responder, as a result of the MSG1. */
446353cd 264static bool_t transport_compute_setupinit_peers(struct site *st,
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265 const struct comm_addr *configured_addrs /* 0 if none or not found */,
266 int n_configured_addrs /* 0 if none or not found */,
a96fda35 267 const struct comm_addr *incoming_packet_addr /* 0 if none */);
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268
269/* Called if we are the responder in a key setup, when the resolve
270 * completes. transport_compute_setupinit_peers will hvae been called
271 * earlier. If _complete is called, we are still doing the key setup
272 * (and we should use the new values for both the rest of the key
273 * setup and the ongoing data exchange); if _tardy is called, the key
274 * setup is done (either completed or not) and only the data peers are
275 * relevant */
90d7e3ad 276static void transport_resolve_complete(struct site *st,
45a14422 277 const struct comm_addr *addrs, int naddrs);
90d7e3ad 278static void transport_resolve_complete_tardy(struct site *st,
45a14422 279 const struct comm_addr *addrs, int naddrs);
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280
281static void transport_xmit(struct site *st, transport_peers *peers,
282 struct buffer_if *buf, bool_t candebug);
283
284 /***** END of transport peers declarations *****/
285
286
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287struct data_key {
288 struct transform_inst_if *transform;
289 uint64_t key_timeout; /* End of life of current key */
290 uint32_t remote_session_id;
291};
292
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293struct site {
294 closure_t cl;
295 struct site_if ops;
296/* configuration information */
297 string_t localname;
298 string_t remotename;
e6d6991c 299 bool_t keepalive;
0391d9ee 300 bool_t local_mobile, peer_mobile; /* Mobile client support */
446353cd 301 int32_t transport_peers_max;
ff05a229 302 string_t tunname; /* localname<->remotename by default, used in logs */
83dbdd3f 303 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
ff05a229 304 int remoteport; /* Port for bootstrapping, optional */
3ed1846a 305 uint32_t mtu_target;
2fe58dfd 306 struct netlink_if *netlink;
59533c16 307 struct comm_if **comms;
5dfe538b 308 struct comm_clientinfo **commclientinfos;
59533c16 309 int ncomms;
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310 struct resolver_if *resolver;
311 struct log_if *log;
312 struct random_if *random;
313 struct rsaprivkey_if *privkey;
2fe58dfd 314 struct rsapubkey_if *pubkey;
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315 struct transform_if **transforms;
316 int ntransforms;
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317 struct dh_if *dh;
318 struct hash_if *hash;
2fe58dfd 319
58650a70 320 uint32_t index; /* Index of this site */
09a385fb 321 uint32_t local_capabilities;
1caa23ff 322 int32_t setup_retries; /* How many times to send setup packets */
e7f8ec2a 323 int32_t setup_retry_interval; /* Initial timeout for setup packets */
4a8aed08 324 int32_t wait_timeout; /* How long to wait if setup unsuccessful */
446353cd 325 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
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326 int32_t key_lifetime; /* How long a key lasts once set up */
327 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
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328 after this time, initiate a new
329 key exchange */
2fe58dfd 330
ffafab08 331 bool_t our_name_later; /* our name > peer name */
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332 uint32_t log_events;
333
334/* runtime information */
335 uint32_t state;
336 uint64_t now; /* Most recently seen time */
dd9209d1 337 bool_t allow_send_prod;
8b978d45 338 bool_t msg1_crossed_logged;
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339 int resolving_count;
340 int resolving_n_results_all;
341 int resolving_n_results_stored;
342 struct comm_addr resolving_results[MAX_PEER_ADDRS];
2fe58dfd 343
ff05a229 344 /* The currently established session */
19e9a588 345 struct data_key current;
02b0959b 346 struct data_key auxiliary_key;
bd98cd6b 347 bool_t auxiliary_is_new;
ff05a229 348 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
bd98cd6b 349 uint64_t auxiliary_renegotiate_key_time;
446353cd 350 transport_peers peers; /* Current address(es) of peer for data traffic */
2fe58dfd 351
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352 /* The current key setup protocol exchange. We can only be
353 involved in one of these at a time. There's a potential for
354 denial of service here (the attacker keeps sending a setup
355 packet; we keep trying to continue the exchange, and have to
356 timeout before we can listen for another setup packet); perhaps
357 we should keep a list of 'bad' sources for setup packets. */
09a385fb 358 uint32_t remote_capabilities;
3ed1846a 359 uint16_t remote_adv_mtu;
5b5f297f 360 struct transform_if *chosen_transform;
2fe58dfd 361 uint32_t setup_session_id;
446353cd 362 transport_peers setup_peers;
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363 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
364 uint8_t remoteN[NONCELEN];
365 struct buffer_if buffer; /* Current outgoing key exchange packet */
05f39b4d 366 struct buffer_if scratch;
4a8aed08 367 int32_t retries; /* Number of retries remaining */
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368 uint64_t timeout; /* Timeout for current state */
369 uint8_t *dhsecret;
370 uint8_t *sharedsecret;
5b5f297f 371 uint32_t sharedsecretlen, sharedsecretallocd;
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372 struct transform_inst_if *new_transform; /* For key setup/verify */
373};
374
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375static uint32_t event_log_priority(struct site *st, uint32_t event)
376{
377 if (!(event&st->log_events))
378 return 0;
379 switch(event) {
380 case LOG_UNEXPECTED: return M_INFO;
381 case LOG_SETUP_INIT: return M_INFO;
382 case LOG_SETUP_TIMEOUT: return M_NOTICE;
383 case LOG_ACTIVATE_KEY: return M_INFO;
384 case LOG_TIMEOUT_KEY: return M_INFO;
385 case LOG_SEC: return M_SECURITY;
386 case LOG_STATE: return M_DEBUG;
387 case LOG_DROP: return M_DEBUG;
388 case LOG_DUMP: return M_DEBUG;
389 case LOG_ERROR: return M_ERR;
390 case LOG_PEER_ADDRS: return M_DEBUG;
391 default: return M_ERR;
392 }
393}
394
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395static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
396FORMAT(printf,3,0);
397static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
2fe58dfd 398{
b2a56f7c 399 uint32_t class;
2fe58dfd 400
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401 class=event_log_priority(st, event);
402 if (class) {
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403 slilog_part(st->log,class,"%s: ",st->tunname);
404 vslilog_part(st->log,class,msg,ap);
405 slilog_part(st->log,class,"\n");
2fe58dfd 406 }
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407}
408
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409static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
410FORMAT(printf,3,4);
411static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
412{
413 va_list ap;
414 va_start(ap,msg);
415 vslog(st,event,msg,ap);
416 va_end(ap);
417}
418
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419static void logtimeout(struct site *st, const char *fmt, ...)
420FORMAT(printf,2,3);
421static void logtimeout(struct site *st, const char *fmt, ...)
422{
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423 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
424 if (!class)
425 return;
426
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427 va_list ap;
428 va_start(ap,fmt);
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429
430 slilog_part(st->log,class,"%s: ",st->tunname);
431 vslilog_part(st->log,class,fmt,ap);
432
433 const char *delim;
434 int i;
435 for (i=0, delim=" (tried ";
436 i<st->setup_peers.npeers;
437 i++, delim=", ") {
438 transport_peer *peer=&st->setup_peers.peers[i];
439 const char *s=comm_addr_to_string(&peer->addr);
440 slilog_part(st->log,class,"%s%s",delim,s);
441 }
442
443 slilog_part(st->log,class,")\n");
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444 va_end(ap);
445}
446
9d3a4132 447static void set_link_quality(struct site *st);
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448static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
449static void delete_one_key(struct site *st, struct data_key *key,
450 const char *reason /* may be 0 meaning don't log*/,
451 const char *which /* ignored if !reasonn */,
452 uint32_t loglevel /* ignored if !reasonn */);
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453static bool_t initiate_key_setup(struct site *st, cstring_t reason,
454 const struct comm_addr *prod_hint);
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455static void enter_state_run(struct site *st);
456static bool_t enter_state_resolve(struct site *st);
83dbdd3f 457static void decrement_resolving_count(struct site *st, int by);
ff05a229 458static bool_t enter_new_state(struct site *st,uint32_t next);
2fe58dfd 459static void enter_state_wait(struct site *st);
05f39b4d 460static void activate_new_key(struct site *st);
2fe58dfd 461
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462static bool_t is_transform_valid(struct transform_inst_if *transform)
463{
fcad4b0b 464 return transform && transform->valid(transform->st);
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465}
466
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467static bool_t current_valid(struct site *st)
468{
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469 return is_transform_valid(st->current.transform);
470}
471
472#define DEFINE_CALL_TRANSFORM(fwdrev) \
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473static transform_apply_return \
474call_transform_##fwdrev(struct site *st, \
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475 struct transform_inst_if *transform, \
476 struct buffer_if *buf, \
477 const char **errmsg) \
478{ \
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479 if (!is_transform_valid(transform)) { \
480 *errmsg="transform not set up"; \
14f78812 481 return transform_apply_err; \
fcad4b0b 482 } \
0afd257e 483 return transform->fwdrev(transform->st,buf,errmsg); \
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484}
485
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486DEFINE_CALL_TRANSFORM(forwards)
487DEFINE_CALL_TRANSFORM(reverse)
488
489static void dispose_transform(struct transform_inst_if **transform_var)
490{
0afd257e 491 struct transform_inst_if *transform=*transform_var;
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492 if (transform) {
493 transform->delkey(transform->st);
494 transform->destroy(transform->st);
495 }
496 *transform_var = 0;
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497}
498
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499#define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
500#define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
501#define CHECK_TYPE(b,t) do { uint32_t type; \
502 CHECK_AVAIL((b),4); \
59635212 503 type=buf_unprepend_uint32((b)); \
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504 if (type!=(t)) return False; } while(0)
505
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506static _Bool type_is_msg34(uint32_t type)
507{
508 return
509 type == LABEL_MSG3 ||
510 type == LABEL_MSG3BIS ||
511 type == LABEL_MSG4;
512}
513
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514struct parsedname {
515 int32_t len;
516 uint8_t *name;
09a385fb 517 struct buffer_if extrainfo;
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518};
519
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520struct msg {
521 uint8_t *hashstart;
522 uint32_t dest;
523 uint32_t source;
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524 struct parsedname remote;
525 struct parsedname local;
09a385fb 526 uint32_t remote_capabilities;
3ed1846a 527 uint16_t remote_mtu;
5b5f297f 528 int capab_transformnum;
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529 uint8_t *nR;
530 uint8_t *nL;
1caa23ff 531 int32_t pklen;
3e8addad 532 char *pk;
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533 int32_t hashlen;
534 int32_t siglen;
3e8addad 535 char *sig;
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536};
537
6f0c71c5 538static _Bool set_new_transform(struct site *st, char *pk)
0afd257e 539{
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540 _Bool ok;
541
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542 /* Make room for the shared key */
543 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
544 assert(st->sharedsecretlen);
545 if (st->sharedsecretlen > st->sharedsecretallocd) {
546 st->sharedsecretallocd=st->sharedsecretlen;
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547 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
548 st->sharedsecretallocd,
549 "site:sharedsecret");
5b5f297f 550 }
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551
552 /* Generate the shared key */
553 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
554 st->sharedsecret,st->sharedsecretlen);
555
556 /* Set up the transform */
557 struct transform_if *generator=st->chosen_transform;
fcad4b0b 558 struct transform_inst_if *generated=generator->create(generator->st);
6f0c71c5 559 ok = generated->setkey(generated->st,st->sharedsecret,
ffafab08 560 st->sharedsecretlen,st->our_name_later);
6f0c71c5 561
fcad4b0b 562 dispose_transform(&st->new_transform);
6f0c71c5 563 if (!ok) return False;
fcad4b0b 564 st->new_transform=generated;
5b5f297f
IJ
565
566 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
567 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
568 st->chosen_transform->capab_transformnum,
569 st->local_capabilities, st->remote_capabilities);
6f0c71c5 570 return True;
0afd257e
IJ
571}
572
09a385fb
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573struct xinfoadd {
574 int32_t lenpos, afternul;
575};
576static void append_string_xinfo_start(struct buffer_if *buf,
577 struct xinfoadd *xia,
578 const char *str)
579 /* Helps construct one of the names with additional info as found
580 * in MSG1..4. Call this function first, then append all the
581 * desired extra info (not including the nul byte) to the buffer,
582 * then call append_string_xinfo_done. */
583{
584 xia->lenpos = buf->size;
585 buf_append_string(buf,str);
586 buf_append_uint8(buf,0);
587 xia->afternul = buf->size;
588}
589static void append_string_xinfo_done(struct buffer_if *buf,
590 struct xinfoadd *xia)
591{
592 /* we just need to adjust the string length */
593 if (buf->size == xia->afternul) {
594 /* no extra info, strip the nul too */
595 buf_unappend_uint8(buf);
596 } else {
597 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
598 }
599}
600
ff05a229
SE
601/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
602 out using a transform of config data supplied by netlink */
fe5e9cc4 603static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
2fe58dfd
SE
604{
605 void *hst;
3b83c932 606 uint8_t *hash;
2fe58dfd
SE
607 string_t dhpub, sig;
608
609 st->retries=st->setup_retries;
610 BUF_ALLOC(&st->buffer,what);
611 buffer_init(&st->buffer,0);
59635212
SE
612 buf_append_uint32(&st->buffer,
613 (type==LABEL_MSG1?0:st->setup_session_id));
58650a70 614 buf_append_uint32(&st->buffer,st->index);
59635212 615 buf_append_uint32(&st->buffer,type);
09a385fb
IJ
616
617 struct xinfoadd xia;
618 append_string_xinfo_start(&st->buffer,&xia,st->localname);
619 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
620 buf_append_uint32(&st->buffer,st->local_capabilities);
621 }
3ed1846a
IJ
622 if (type_is_msg34(type)) {
623 buf_append_uint16(&st->buffer,st->mtu_target);
624 }
09a385fb
IJ
625 append_string_xinfo_done(&st->buffer,&xia);
626
2fe58dfd 627 buf_append_string(&st->buffer,st->remotename);
4f28e77e 628 BUF_ADD_OBJ(append,&st->buffer,st->localN);
2fe58dfd 629 if (type==LABEL_MSG1) return True;
4f28e77e 630 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
2fe58dfd 631 if (type==LABEL_MSG2) return True;
3b83c932
SE
632
633 if (hacky_par_mid_failnow()) return False;
634
5b5f297f
IJ
635 if (type==LABEL_MSG3BIS)
636 buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
637
2fe58dfd
SE
638 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
639 buf_append_string(&st->buffer,dhpub);
640 free(dhpub);
3b83c932 641 hash=safe_malloc(st->hash->len, "generate_msg");
2fe58dfd
SE
642 hst=st->hash->init();
643 st->hash->update(hst,st->buffer.start,st->buffer.size);
644 st->hash->final(hst,hash);
645 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
646 buf_append_string(&st->buffer,sig);
647 free(sig);
3b83c932 648 free(hash);
2fe58dfd
SE
649 return True;
650}
651
1737eeef
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652static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
653{
654 CHECK_AVAIL(msg,2);
655 nm->len=buf_unprepend_uint16(msg);
656 CHECK_AVAIL(msg,nm->len);
657 nm->name=buf_unprepend(msg,nm->len);
658 uint8_t *nul=memchr(nm->name,0,nm->len);
659 if (!nul) {
09a385fb 660 buffer_readonly_view(&nm->extrainfo,0,0);
1737eeef 661 } else {
09a385fb 662 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
1737eeef
IJ
663 nm->len=nul-nm->name;
664 }
665 return True;
666}
667
2fe58dfd
SE
668static bool_t unpick_msg(struct site *st, uint32_t type,
669 struct buffer_if *msg, struct msg *m)
670{
5b5f297f 671 m->capab_transformnum=-1;
2fe58dfd
SE
672 m->hashstart=msg->start;
673 CHECK_AVAIL(msg,4);
59635212 674 m->dest=buf_unprepend_uint32(msg);
2fe58dfd 675 CHECK_AVAIL(msg,4);
59635212 676 m->source=buf_unprepend_uint32(msg);
2fe58dfd 677 CHECK_TYPE(msg,type);
1737eeef 678 if (!unpick_name(msg,&m->remote)) return False;
09a385fb 679 m->remote_capabilities=0;
3ed1846a 680 m->remote_mtu=0;
09a385fb
IJ
681 if (m->remote.extrainfo.size) {
682 CHECK_AVAIL(&m->remote.extrainfo,4);
683 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
684 }
3ed1846a
IJ
685 if (type_is_msg34(type) && m->remote.extrainfo.size) {
686 CHECK_AVAIL(&m->remote.extrainfo,2);
687 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
688 }
1737eeef 689 if (!unpick_name(msg,&m->local)) return False;
dd9209d1
IJ
690 if (type==LABEL_PROD) {
691 CHECK_EMPTY(msg);
692 return True;
693 }
2fe58dfd
SE
694 CHECK_AVAIL(msg,NONCELEN);
695 m->nR=buf_unprepend(msg,NONCELEN);
696 if (type==LABEL_MSG1) {
697 CHECK_EMPTY(msg);
698 return True;
699 }
700 CHECK_AVAIL(msg,NONCELEN);
701 m->nL=buf_unprepend(msg,NONCELEN);
702 if (type==LABEL_MSG2) {
703 CHECK_EMPTY(msg);
704 return True;
705 }
5b5f297f
IJ
706 if (type==LABEL_MSG3BIS) {
707 CHECK_AVAIL(msg,1);
708 m->capab_transformnum = buf_unprepend_uint8(msg);
709 } else {
710 m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
711 }
2fe58dfd 712 CHECK_AVAIL(msg,2);
59635212 713 m->pklen=buf_unprepend_uint16(msg);
2fe58dfd
SE
714 CHECK_AVAIL(msg,m->pklen);
715 m->pk=buf_unprepend(msg,m->pklen);
716 m->hashlen=msg->start-m->hashstart;
717 CHECK_AVAIL(msg,2);
59635212 718 m->siglen=buf_unprepend_uint16(msg);
2fe58dfd
SE
719 CHECK_AVAIL(msg,m->siglen);
720 m->sig=buf_unprepend(msg,m->siglen);
721 CHECK_EMPTY(msg);
534fb389
MW
722
723 /* In `process_msg3_msg4' below, we assume that we can write a nul
724 * terminator following the signature. Make sure there's enough space.
725 */
726 if (msg->start >= msg->base + msg->alloclen)
727 return False;
728
2fe58dfd
SE
729 return True;
730}
731
1737eeef
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732static bool_t name_matches(const struct parsedname *nm, const char *expected)
733{
734 int expected_len=strlen(expected);
735 return
736 nm->len == expected_len &&
737 !memcmp(nm->name, expected, expected_len);
738}
739
ff05a229 740static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
fe5e9cc4 741 cstring_t *error)
ff05a229
SE
742{
743 if (type==LABEL_MSG1) return True;
744
745 /* Check that the site names and our nonce have been sent
746 back correctly, and then store our peer's nonce. */
1737eeef 747 if (!name_matches(&m->remote,st->remotename)) {
ff05a229
SE
748 *error="wrong remote site name";
749 return False;
750 }
1737eeef 751 if (!name_matches(&m->local,st->localname)) {
ff05a229
SE
752 *error="wrong local site name";
753 return False;
754 }
755 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
756 *error="wrong locally-generated nonce";
757 return False;
758 }
759 if (type==LABEL_MSG2) return True;
5ad34db2 760 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
ff05a229
SE
761 *error="wrong remotely-generated nonce";
762 return False;
763 }
09a385fb
IJ
764 /* MSG3 has complicated rules about capabilities, which are
765 * handled in process_msg3. */
5b5f297f 766 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
09a385fb
IJ
767 if (m->remote_capabilities!=st->remote_capabilities) {
768 *error="remote capabilities changed";
769 return False;
770 }
ff05a229
SE
771 if (type==LABEL_MSG4) return True;
772 *error="unknown message type";
773 return False;
774}
775
2fe58dfd
SE
776static bool_t generate_msg1(struct site *st)
777{
778 st->random->generate(st->random->st,NONCELEN,st->localN);
779 return generate_msg(st,LABEL_MSG1,"site:MSG1");
780}
781
782static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
7e29719e 783 const struct comm_addr *src, struct msg *m)
2fe58dfd 784{
2fe58dfd
SE
785 /* We've already determined we're in an appropriate state to
786 process an incoming MSG1, and that the MSG1 has correct values
787 of A and B. */
788
7e29719e 789 st->setup_session_id=m->source;
09a385fb 790 st->remote_capabilities=m->remote_capabilities;
7e29719e 791 memcpy(st->remoteN,m->nR,NONCELEN);
2fe58dfd
SE
792 return True;
793}
794
795static bool_t generate_msg2(struct site *st)
796{
797 st->random->generate(st->random->st,NONCELEN,st->localN);
798 return generate_msg(st,LABEL_MSG2,"site:MSG2");
799}
800
801static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
a15faeb2 802 const struct comm_addr *src)
2fe58dfd
SE
803{
804 struct msg m;
fe5e9cc4 805 cstring_t err;
2fe58dfd
SE
806
807 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
ff05a229
SE
808 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
809 slog(st,LOG_SEC,"msg2: %s",err);
2fe58dfd
SE
810 return False;
811 }
812 st->setup_session_id=m.source;
09a385fb 813 st->remote_capabilities=m.remote_capabilities;
5b5f297f
IJ
814
815 /* Select the transform to use */
816
817 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
818 if (!remote_transforms)
819 /* old secnets only had this one transform */
820 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
821
822 struct transform_if *ti;
823 int i;
824 for (i=0; i<st->ntransforms; i++) {
825 ti=st->transforms[i];
826 if ((1UL << ti->capab_transformnum) & remote_transforms)
827 goto transform_found;
828 }
829 slog(st,LOG_ERROR,"no transforms in common"
830 " (us %#"PRIx32"; them: %#"PRIx32")",
831 st->local_capabilities & CAPAB_TRANSFORM_MASK,
832 remote_transforms);
833 return False;
834 transform_found:
835 st->chosen_transform=ti;
836
2fe58dfd
SE
837 memcpy(st->remoteN,m.nR,NONCELEN);
838 return True;
839}
840
841static bool_t generate_msg3(struct site *st)
842{
843 /* Now we have our nonce and their nonce. Think of a secret key,
844 and create message number 3. */
845 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
5b5f297f
IJ
846 return generate_msg(st,
847 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
848 ? LABEL_MSG3BIS : LABEL_MSG3),
849 "site:MSG3");
2fe58dfd
SE
850}
851
e001e8c0
IJ
852static bool_t process_msg3_msg4(struct site *st, struct msg *m)
853{
854 uint8_t *hash;
855 void *hst;
856
857 /* Check signature and store g^x mod m */
858 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
859 hst=st->hash->init();
860 st->hash->update(hst,m->hashstart,m->hashlen);
861 st->hash->final(hst,hash);
534fb389 862 /* Terminate signature with a '0' - already checked that this will fit */
e001e8c0
IJ
863 m->sig[m->siglen]=0;
864 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
865 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
866 free(hash);
867 return False;
868 }
869 free(hash);
870
3ed1846a
IJ
871 st->remote_adv_mtu=m->remote_mtu;
872
e001e8c0
IJ
873 return True;
874}
875
2fe58dfd 876static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
5b5f297f 877 const struct comm_addr *src, uint32_t msgtype)
2fe58dfd
SE
878{
879 struct msg m;
fe5e9cc4 880 cstring_t err;
2fe58dfd 881
5b5f297f
IJ
882 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
883
884 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
885 if (!check_msg(st,msgtype,&m,&err)) {
ff05a229 886 slog(st,LOG_SEC,"msg3: %s",err);
2fe58dfd
SE
887 return False;
888 }
09a385fb
IJ
889 uint32_t capab_adv_late = m.remote_capabilities
890 & ~st->remote_capabilities & CAPAB_EARLY;
891 if (capab_adv_late) {
892 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
893 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
894 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
895 return False;
896 }
897 st->remote_capabilities|=m.remote_capabilities;
ff05a229 898
5b5f297f
IJ
899 struct transform_if *ti;
900 int i;
901 for (i=0; i<st->ntransforms; i++) {
902 ti=st->transforms[i];
903 if (ti->capab_transformnum == m.capab_transformnum)
904 goto transform_found;
905 }
906 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
907 m.capab_transformnum);
908 return False;
909 transform_found:
910 st->chosen_transform=ti;
911
e001e8c0 912 if (!process_msg3_msg4(st,&m))
2fe58dfd 913 return False;
2fe58dfd
SE
914
915 /* Terminate their DH public key with a '0' */
916 m.pk[m.pklen]=0;
917 /* Invent our DH secret key */
918 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
919
5b5f297f 920 /* Generate the shared key and set up the transform */
6f0c71c5 921 if (!set_new_transform(st,m.pk)) return False;
2fe58dfd
SE
922
923 return True;
924}
925
926static bool_t generate_msg4(struct site *st)
927{
928 /* We have both nonces, their public key and our private key. Generate
929 our public key, sign it and send it to them. */
930 return generate_msg(st,LABEL_MSG4,"site:MSG4");
931}
932
933static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
a15faeb2 934 const struct comm_addr *src)
2fe58dfd
SE
935{
936 struct msg m;
fe5e9cc4 937 cstring_t err;
2fe58dfd
SE
938
939 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
ff05a229
SE
940 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
941 slog(st,LOG_SEC,"msg4: %s",err);
2fe58dfd
SE
942 return False;
943 }
944
e001e8c0 945 if (!process_msg3_msg4(st,&m))
2fe58dfd 946 return False;
2fe58dfd
SE
947
948 /* Terminate their DH public key with a '0' */
949 m.pk[m.pklen]=0;
5b5f297f
IJ
950
951 /* Generate the shared key and set up the transform */
6f0c71c5 952 if (!set_new_transform(st,m.pk)) return False;
2fe58dfd
SE
953
954 return True;
955}
956
2fe58dfd
SE
957struct msg0 {
958 uint32_t dest;
959 uint32_t source;
960 uint32_t type;
961};
962
963static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
964 struct msg0 *m)
965{
966 CHECK_AVAIL(msg0,4);
59635212 967 m->dest=buf_unprepend_uint32(msg0);
2fe58dfd 968 CHECK_AVAIL(msg0,4);
59635212 969 m->source=buf_unprepend_uint32(msg0);
2fe58dfd 970 CHECK_AVAIL(msg0,4);
59635212 971 m->type=buf_unprepend_uint32(msg0);
2fe58dfd
SE
972 return True;
973 /* Leaves transformed part of buffer untouched */
974}
975
ff05a229
SE
976static bool_t generate_msg5(struct site *st)
977{
fe5e9cc4 978 cstring_t transform_err;
ff05a229
SE
979
980 BUF_ALLOC(&st->buffer,"site:MSG5");
981 /* We are going to add four words to the message */
3abd18e8 982 buffer_init(&st->buffer,calculate_max_start_pad());
ff05a229
SE
983 /* Give the netlink code an opportunity to put its own stuff in the
984 message (configuration information, etc.) */
ff05a229 985 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
0afd257e
IJ
986 if (call_transform_forwards(st,st->new_transform,
987 &st->buffer,&transform_err))
988 return False;
ff05a229 989 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
58650a70 990 buf_prepend_uint32(&st->buffer,st->index);
ff05a229
SE
991 buf_prepend_uint32(&st->buffer,st->setup_session_id);
992
993 st->retries=st->setup_retries;
994 return True;
995}
996
2fe58dfd 997static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
c90cc2a7
IJ
998 const struct comm_addr *src,
999 struct transform_inst_if *transform)
2fe58dfd
SE
1000{
1001 struct msg0 m;
fe5e9cc4 1002 cstring_t transform_err;
2fe58dfd
SE
1003
1004 if (!unpick_msg0(st,msg5,&m)) return False;
1005
0afd257e 1006 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
2fe58dfd 1007 /* There's a problem */
59635212 1008 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
2fe58dfd
SE
1009 return False;
1010 }
1011 /* Buffer should now contain untransformed PING packet data */
1012 CHECK_AVAIL(msg5,4);
59635212 1013 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
ff05a229 1014 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
2fe58dfd
SE
1015 return False;
1016 }
ff7cdc9e
IJ
1017 /* Older versions of secnet used to write some config data here
1018 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE
1019 return True;
1020}
1021
c90cc2a7
IJ
1022static void create_msg6(struct site *st, struct transform_inst_if *transform,
1023 uint32_t session_id)
2fe58dfd 1024{
fe5e9cc4 1025 cstring_t transform_err;
2fe58dfd
SE
1026
1027 BUF_ALLOC(&st->buffer,"site:MSG6");
ff05a229 1028 /* We are going to add four words to the message */
3abd18e8 1029 buffer_init(&st->buffer,calculate_max_start_pad());
794f2398
SE
1030 /* Give the netlink code an opportunity to put its own stuff in the
1031 message (configuration information, etc.) */
ff05a229 1032 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
14f78812
IJ
1033 transform_apply_return problem =
1034 call_transform_forwards(st,transform,
1035 &st->buffer,&transform_err);
0afd257e 1036 assert(!problem);
59635212 1037 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
58650a70 1038 buf_prepend_uint32(&st->buffer,st->index);
c90cc2a7
IJ
1039 buf_prepend_uint32(&st->buffer,session_id);
1040}
2fe58dfd 1041
c90cc2a7
IJ
1042static bool_t generate_msg6(struct site *st)
1043{
0afd257e
IJ
1044 if (!is_transform_valid(st->new_transform))
1045 return False;
c90cc2a7 1046 create_msg6(st,st->new_transform,st->setup_session_id);
ff05a229 1047 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
2fe58dfd
SE
1048 return True;
1049}
1050
1051static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
a15faeb2 1052 const struct comm_addr *src)
2fe58dfd
SE
1053{
1054 struct msg0 m;
fe5e9cc4 1055 cstring_t transform_err;
2fe58dfd
SE
1056
1057 if (!unpick_msg0(st,msg6,&m)) return False;
1058
0afd257e 1059 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
2fe58dfd 1060 /* There's a problem */
59635212 1061 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
2fe58dfd
SE
1062 return False;
1063 }
1064 /* Buffer should now contain untransformed PING packet data */
1065 CHECK_AVAIL(msg6,4);
59635212
SE
1066 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1067 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
2fe58dfd
SE
1068 return False;
1069 }
ff7cdc9e
IJ
1070 /* Older versions of secnet used to write some config data here
1071 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE
1072 return True;
1073}
1074
3cdb830c
IJ
1075static transform_apply_return
1076decrypt_msg0(struct site *st, struct buffer_if *msg0,
48b97423 1077 const struct comm_addr *src)
2fe58dfd 1078{
02b0959b 1079 cstring_t transform_err, auxkey_err, newkey_err="n/a";
065e1922 1080 struct msg0 m;
14f78812 1081 transform_apply_return problem;
2fe58dfd 1082
2fe58dfd
SE
1083 if (!unpick_msg0(st,msg0,&m)) return False;
1084
05f39b4d
IJ
1085 /* Keep a copy so we can try decrypting it with multiple keys */
1086 buffer_copy(&st->scratch, msg0);
1087
0afd257e
IJ
1088 problem = call_transform_reverse(st,st->current.transform,
1089 msg0,&transform_err);
02b0959b 1090 if (!problem) {
bd98cd6b
IJ
1091 if (!st->auxiliary_is_new)
1092 delete_one_key(st,&st->auxiliary_key,
1093 "peer has used new key","auxiliary key",LOG_SEC);
3cdb830c 1094 return 0;
02b0959b 1095 }
31dd0788
IJ
1096 if (transform_apply_return_badseq(problem))
1097 goto badseq;
07e4774c 1098
02b0959b 1099 buffer_copy(msg0, &st->scratch);
fcad4b0b
IJ
1100 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1101 msg0,&auxkey_err);
14f78812 1102 if (!problem) {
02b0959b 1103 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
bd98cd6b
IJ
1104 if (st->auxiliary_is_new) {
1105 /* We previously timed out in state SENTMSG5 but it turns
1106 * out that our peer did in fact get our MSG5 and is
1107 * using the new key. So we should switch to it too. */
1108 /* This is a bit like activate_new_key. */
1109 struct data_key t;
1110 t=st->current;
1111 st->current=st->auxiliary_key;
1112 st->auxiliary_key=t;
1113
1114 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1115 "previous key",LOG_SEC);
1116 st->auxiliary_is_new=0;
1117 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1118 }
3cdb830c 1119 return 0;
02b0959b 1120 }
31dd0788
IJ
1121 if (transform_apply_return_badseq(problem))
1122 goto badseq;
02b0959b 1123
05f39b4d
IJ
1124 if (st->state==SITE_SENTMSG5) {
1125 buffer_copy(msg0, &st->scratch);
0afd257e
IJ
1126 problem = call_transform_reverse(st,st->new_transform,
1127 msg0,&newkey_err);
48b97423 1128 if (!problem) {
05f39b4d
IJ
1129 /* It looks like we didn't get the peer's MSG6 */
1130 /* This is like a cut-down enter_new_state(SITE_RUN) */
1131 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1132 BUF_FREE(&st->buffer);
1133 st->timeout=0;
1134 activate_new_key(st);
3cdb830c 1135 return 0; /* do process the data in this packet */
05f39b4d 1136 }
31dd0788
IJ
1137 if (transform_apply_return_badseq(problem))
1138 goto badseq;
05f39b4d
IJ
1139 }
1140
02b0959b
IJ
1141 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1142 transform_err,auxkey_err,newkey_err);
dd9209d1 1143 initiate_key_setup(st,"incoming message would not decrypt",0);
48b97423 1144 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
3cdb830c
IJ
1145 assert(problem);
1146 return problem;
48b97423 1147
31dd0788
IJ
1148 badseq:
1149 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
37acaef1
IJ
1150 assert(problem);
1151 return problem;
065e1922
IJ
1152}
1153
1154static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1155 const struct comm_addr *src)
1156{
1157 uint32_t type;
3cdb830c 1158 transform_apply_return problem;
065e1922 1159
3cdb830c 1160 problem = decrypt_msg0(st,msg0,src);
cbc25196
IJ
1161 if (problem==transform_apply_seqdupe) {
1162 /* We recently received another copy of this packet, maybe due
1163 * to polypath. That's not a problem; indeed, for the
1164 * purposes of transport address management it is a success.
1165 * But we don't want to process the packet. */
1166 transport_data_msgok(st,src);
1167 return False;
1168 }
3cdb830c 1169 if (problem)
065e1922
IJ
1170 return False;
1171
2fe58dfd 1172 CHECK_AVAIL(msg0,4);
59635212 1173 type=buf_unprepend_uint32(msg0);
2fe58dfd 1174 switch(type) {
794f2398
SE
1175 case LABEL_MSG7:
1176 /* We must forget about the current session. */
1d388569 1177 delete_keys(st,"request from peer",LOG_SEC);
e0d2e637
IJ
1178 /* probably, the peer is shutting down, and this is going to fail,
1179 * but we need to be trying to bring the link up again */
1180 if (st->keepalive)
1181 initiate_key_setup(st,"peer requested key teardown",0);
794f2398 1182 return True;
2fe58dfd
SE
1183 case LABEL_MSG9:
1184 /* Deliver to netlink layer */
469fd1d9 1185 st->netlink->deliver(st->netlink->st,msg0);
446353cd 1186 transport_data_msgok(st,src);
837cf01e
IJ
1187 /* See whether we should start negotiating a new key */
1188 if (st->now > st->renegotiate_key_time)
dd9209d1 1189 initiate_key_setup(st,"incoming packet in renegotiation window",0);
2fe58dfd 1190 return True;
2fe58dfd 1191 default:
ff05a229
SE
1192 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1193 "(unknown)",type);
2fe58dfd
SE
1194 break;
1195 }
1196 return False;
1197}
1198
1199static void dump_packet(struct site *st, struct buffer_if *buf,
62846523
IJ
1200 const struct comm_addr *addr, bool_t incoming,
1201 bool_t ok)
2fe58dfd 1202{
0a6cbade
IJ
1203 uint32_t dest=get_uint32(buf->start);
1204 uint32_t source=get_uint32(buf->start+4);
1205 uint32_t msgtype=get_uint32(buf->start+8);
2fe58dfd
SE
1206
1207 if (st->log_events & LOG_DUMP)
62846523 1208 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
040ee979 1209 st->tunname,incoming?"incoming":"outgoing",
62846523
IJ
1210 dest,source,msgtype,comm_addr_to_string(addr),
1211 ok?"":" - fail");
2fe58dfd
SE
1212}
1213
eff48c12
IJ
1214static bool_t comm_addr_sendmsg(struct site *st,
1215 const struct comm_addr *dest,
1216 struct buffer_if *buf)
1217{
5dfe538b
IJ
1218 int i;
1219 struct comm_clientinfo *commclientinfo = 0;
1220
1221 for (i=0; i < st->ncomms; i++) {
1222 if (st->comms[i] == dest->comm) {
1223 commclientinfo = st->commclientinfos[i];
1224 break;
1225 }
1226 }
1227 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
eff48c12
IJ
1228}
1229
2fe58dfd
SE
1230static uint32_t site_status(void *st)
1231{
1232 return 0;
1233}
1234
1235static bool_t send_msg(struct site *st)
1236{
1237 if (st->retries>0) {
446353cd 1238 transport_xmit(st, &st->setup_peers, &st->buffer, True);
e7f8ec2a 1239 st->timeout=st->now+st->setup_retry_interval;
2fe58dfd
SE
1240 st->retries--;
1241 return True;
bd98cd6b 1242 } else if (st->state==SITE_SENTMSG5) {
4f3c75ac 1243 logtimeout(st,"timed out sending MSG5, stashing new key");
bd98cd6b
IJ
1244 /* We stash the key we have produced, in case it turns out that
1245 * our peer did see our MSG5 after all and starts using it. */
1246 /* This is a bit like some of activate_new_key */
1247 struct transform_inst_if *t;
1248 t=st->auxiliary_key.transform;
1249 st->auxiliary_key.transform=st->new_transform;
1250 st->new_transform=t;
0afd257e 1251 dispose_transform(&st->new_transform);
bd98cd6b 1252
bd98cd6b
IJ
1253 st->auxiliary_is_new=1;
1254 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1255 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1256 st->auxiliary_key.remote_session_id=st->setup_session_id;
1257
1258 enter_state_wait(st);
1259 return False;
2fe58dfd 1260 } else {
4f3c75ac 1261 logtimeout(st,"timed out sending key setup packet "
3454dce4 1262 "(in state %s)",state_name(st->state));
2fe58dfd
SE
1263 enter_state_wait(st);
1264 return False;
1265 }
1266}
1267
cc420616 1268static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
83dbdd3f 1269 int stored_naddrs, int all_naddrs,
bc07424d 1270 const char *address, const char *failwhy)
2fe58dfd
SE
1271{
1272 struct site *st=sst;
1273
83dbdd3f
IJ
1274 if (!stored_naddrs) {
1275 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1276 } else {
1277 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1278 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1279
1280 int space=st->transport_peers_max-st->resolving_n_results_stored;
1281 int n_tocopy=MIN(stored_naddrs,space);
1282 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1283 addrs,
1284 n_tocopy);
1285 st->resolving_n_results_stored += n_tocopy;
1286 st->resolving_n_results_all += all_naddrs;
1287 }
1288
1289 decrement_resolving_count(st,1);
1290}
1291
1292static void decrement_resolving_count(struct site *st, int by)
1293{
1294 assert(st->resolving_count>0);
1295 st->resolving_count-=by;
1296
1297 if (st->resolving_count)
1298 return;
1299
1300 /* OK, we are done with them all. Handle combined results. */
1301
1302 const struct comm_addr *addrs=st->resolving_results;
1303 int naddrs=st->resolving_n_results_stored;
1304 assert(naddrs<=st->transport_peers_max);
5c19b79c 1305
cc420616 1306 if (naddrs) {
83dbdd3f 1307 if (naddrs != st->resolving_n_results_all) {
cc420616
IJ
1308 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1309 " yielded too many results (%d > %d), some ignored",
83dbdd3f 1310 st->resolving_n_results_all, naddrs);
cc420616 1311 }
83dbdd3f 1312 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
d9d101ea 1313 naddrs, iaddr_to_string(&addrs[0].ia));;
446353cd 1314 }
c22c3541
IJ
1315
1316 switch (st->state) {
1317 case SITE_RESOLVE:
45a14422 1318 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
c22c3541
IJ
1319 enter_new_state(st,SITE_SENTMSG1);
1320 } else {
1321 /* Can't figure out who to try to to talk to */
1322 slog(st,LOG_SETUP_INIT,
1323 "key exchange failed: cannot find peer address");
1324 enter_state_run(st);
1325 }
1326 break;
1327 case SITE_SENTMSG1: case SITE_SENTMSG2:
1328 case SITE_SENTMSG3: case SITE_SENTMSG4:
1329 case SITE_SENTMSG5:
45a14422 1330 if (naddrs) {
c22c3541
IJ
1331 /* We start using the address immediately for data too.
1332 * It's best to store it in st->peers now because we might
1333 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1334 * the new key (without updating the data peer addrs). */
45a14422 1335 transport_resolve_complete(st,addrs,naddrs);
c22c3541
IJ
1336 } else if (st->local_mobile) {
1337 /* We can't let this rest because we may have a peer
1338 * address which will break in the future. */
83dbdd3f
IJ
1339 slog(st,LOG_SETUP_INIT,"resolution failed: "
1340 "abandoning key exchange");
c22c3541
IJ
1341 enter_state_wait(st);
1342 } else {
83dbdd3f 1343 slog(st,LOG_SETUP_INIT,"resolution failed: "
c22c3541 1344 " continuing to use source address of peer's packets"
83dbdd3f 1345 " for key exchange and ultimately data");
c22c3541
IJ
1346 }
1347 break;
1348 case SITE_RUN:
45a14422 1349 if (naddrs) {
83dbdd3f
IJ
1350 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1351 " updating peer address(es)");
45a14422 1352 transport_resolve_complete_tardy(st,addrs,naddrs);
c22c3541
IJ
1353 } else if (st->local_mobile) {
1354 /* Not very good. We should queue (another) renegotiation
1355 * so that we can update the peer address. */
1356 st->key_renegotiate_time=st->now+st->wait_timeout;
1357 } else {
83dbdd3f
IJ
1358 slog(st,LOG_SETUP_INIT,"resolution failed: "
1359 " continuing to use source address of peer's packets");
c22c3541
IJ
1360 }
1361 break;
1362 case SITE_WAIT:
1363 case SITE_STOP:
1364 /* oh well */
1365 break;
2fe58dfd
SE
1366 }
1367}
1368
dd9209d1
IJ
1369static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1370 const struct comm_addr *prod_hint)
9d3a4132 1371{
77effe1d 1372 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
9d3a4132 1373 if (st->state!=SITE_RUN) return False;
794f2398 1374 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
83dbdd3f
IJ
1375 if (st->addresses) {
1376 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
9d3a4132 1377 return enter_state_resolve(st);
45a14422 1378 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
ff05a229 1379 return enter_new_state(st,SITE_SENTMSG1);
9d3a4132 1380 }
ff05a229 1381 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
9d3a4132
SE
1382 return False;
1383}
1384
2fe58dfd
SE
1385static void activate_new_key(struct site *st)
1386{
1387 struct transform_inst_if *t;
1388
02b0959b
IJ
1389 /* We have three transform instances, which we swap between old,
1390 active and setup */
1391 t=st->auxiliary_key.transform;
1392 st->auxiliary_key.transform=st->current.transform;
19e9a588 1393 st->current.transform=st->new_transform;
2fe58dfd 1394 st->new_transform=t;
0afd257e 1395 dispose_transform(&st->new_transform);
2fe58dfd 1396
2fe58dfd 1397 st->timeout=0;
bd98cd6b 1398 st->auxiliary_is_new=0;
02b0959b 1399 st->auxiliary_key.key_timeout=st->current.key_timeout;
19e9a588 1400 st->current.key_timeout=st->now+st->key_lifetime;
ff05a229 1401 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
446353cd 1402 transport_peers_copy(st,&st->peers,&st->setup_peers);
19e9a588 1403 st->current.remote_session_id=st->setup_session_id;
2fe58dfd 1404
3ed1846a
IJ
1405 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1406 * But their mtu be unspecified, in which case we just use ours. */
1407 uint32_t intersite_mtu=
1408 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1409 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1410
1411 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1412 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1413 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
9d3a4132 1414 enter_state_run(st);
2fe58dfd
SE
1415}
1416
1d388569
IJ
1417static void delete_one_key(struct site *st, struct data_key *key,
1418 cstring_t reason, cstring_t which, uint32_t loglevel)
1419{
0afd257e 1420 if (!is_transform_valid(key->transform)) return;
1d388569 1421 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
0afd257e 1422 dispose_transform(&key->transform);
1d388569
IJ
1423 key->key_timeout=0;
1424}
1425
1426static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
794f2398 1427{
3d8d8f4e 1428 if (current_valid(st)) {
794f2398
SE
1429 slog(st,loglevel,"session closed (%s)",reason);
1430
1d388569 1431 delete_one_key(st,&st->current,0,0,0);
794f2398
SE
1432 set_link_quality(st);
1433 }
02b0959b 1434 delete_one_key(st,&st->auxiliary_key,0,0,0);
794f2398
SE
1435}
1436
2fe58dfd
SE
1437static void state_assert(struct site *st, bool_t ok)
1438{
4f5e39ec 1439 if (!ok) fatal("site:state_assert");
2fe58dfd
SE
1440}
1441
1442static void enter_state_stop(struct site *st)
1443{
1444 st->state=SITE_STOP;
1445 st->timeout=0;
1d388569 1446 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
0afd257e 1447 dispose_transform(&st->new_transform);
2fe58dfd
SE
1448}
1449
9d3a4132
SE
1450static void set_link_quality(struct site *st)
1451{
1452 uint32_t quality;
3d8d8f4e 1453 if (current_valid(st))
9d3a4132
SE
1454 quality=LINK_QUALITY_UP;
1455 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1456 quality=LINK_QUALITY_DOWN;
83dbdd3f 1457 else if (st->addresses)
9d3a4132 1458 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
446353cd 1459 else if (transport_peers_valid(&st->peers))
9d3a4132
SE
1460 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1461 else
1462 quality=LINK_QUALITY_DOWN;
1463
469fd1d9 1464 st->netlink->set_quality(st->netlink->st,quality);
9d3a4132
SE
1465}
1466
2fe58dfd
SE
1467static void enter_state_run(struct site *st)
1468{
1469 slog(st,LOG_STATE,"entering state RUN");
1470 st->state=SITE_RUN;
1471 st->timeout=0;
9d3a4132 1472
ff05a229 1473 st->setup_session_id=0;
446353cd 1474 transport_peers_clear(st,&st->setup_peers);
4f28e77e
IJ
1475 FILLZERO(st->localN);
1476 FILLZERO(st->remoteN);
0afd257e 1477 dispose_transform(&st->new_transform);
ff05a229 1478 memset(st->dhsecret,0,st->dh->len);
f7857c83 1479 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
9d3a4132 1480 set_link_quality(st);
e6d6991c
IJ
1481
1482 if (st->keepalive && !current_valid(st))
1483 initiate_key_setup(st, "keepalive", 0);
2fe58dfd
SE
1484}
1485
5c19b79c
IJ
1486static bool_t ensure_resolving(struct site *st)
1487{
1488 /* Reentrancy hazard: may call site_resolve_callback and hence
1489 * enter_new_state, enter_state_* and generate_msg*. */
83dbdd3f 1490 if (st->resolving_count)
5c19b79c
IJ
1491 return True;
1492
83dbdd3f 1493 assert(st->addresses);
4ac8a7d2 1494
5c19b79c 1495 /* resolver->request might reentrantly call site_resolve_callback
83dbdd3f
IJ
1496 * which will decrement st->resolving, so we need to increment it
1497 * twice beforehand to prevent decrement from thinking we're
1498 * finished, and decrement it ourselves. Alternatively if
1499 * everything fails then there are no callbacks due and we simply
1500 * set it to 0 and return false.. */
1501 st->resolving_n_results_stored=0;
1502 st->resolving_n_results_all=0;
1503 st->resolving_count+=2;
1504 const char **addrp=st->addresses;
1505 const char *address;
1506 bool_t anyok=False;
1507 for (; (address=*addrp++); ) {
1508 bool_t ok = st->resolver->request(st->resolver->st,address,
1509 st->remoteport,st->comms[0],
1510 site_resolve_callback,st);
1511 if (ok)
1512 st->resolving_count++;
1513 anyok|=ok;
1514 }
1515 if (!anyok) {
1516 st->resolving_count=0;
1517 return False;
1518 }
1519 decrement_resolving_count(st,2);
1520 return True;
5c19b79c
IJ
1521}
1522
2fe58dfd
SE
1523static bool_t enter_state_resolve(struct site *st)
1524{
77effe1d 1525 /* Reentrancy hazard! See ensure_resolving. */
2fe58dfd
SE
1526 state_assert(st,st->state==SITE_RUN);
1527 slog(st,LOG_STATE,"entering state RESOLVE");
1528 st->state=SITE_RESOLVE;
5c19b79c 1529 return ensure_resolving(st);
2fe58dfd
SE
1530}
1531
ff05a229 1532static bool_t enter_new_state(struct site *st, uint32_t next)
2fe58dfd 1533{
ff05a229 1534 bool_t (*gen)(struct site *st);
3b83c932
SE
1535 int r;
1536
ff05a229
SE
1537 slog(st,LOG_STATE,"entering state %s",state_name(next));
1538 switch(next) {
1539 case SITE_SENTMSG1:
1540 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1541 gen=generate_msg1;
8b978d45 1542 st->msg1_crossed_logged = False;
ff05a229
SE
1543 break;
1544 case SITE_SENTMSG2:
1545 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1546 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1547 gen=generate_msg2;
1548 break;
1549 case SITE_SENTMSG3:
1550 state_assert(st,st->state==SITE_SENTMSG1);
1551 BUF_FREE(&st->buffer);
1552 gen=generate_msg3;
1553 break;
1554 case SITE_SENTMSG4:
1555 state_assert(st,st->state==SITE_SENTMSG2);
1556 BUF_FREE(&st->buffer);
1557 gen=generate_msg4;
1558 break;
1559 case SITE_SENTMSG5:
1560 state_assert(st,st->state==SITE_SENTMSG3);
1561 BUF_FREE(&st->buffer);
1562 gen=generate_msg5;
1563 break;
1564 case SITE_RUN:
1565 state_assert(st,st->state==SITE_SENTMSG4);
1566 BUF_FREE(&st->buffer);
1567 gen=generate_msg6;
1568 break;
1569 default:
1570 gen=NULL;
4f5e39ec 1571 fatal("enter_new_state(%s): invalid new state",state_name(next));
ff05a229 1572 break;
2fe58dfd 1573 }
2fe58dfd 1574
3b83c932
SE
1575 if (hacky_par_start_failnow()) return False;
1576
1577 r= gen(st) && send_msg(st);
1578
1579 hacky_par_end(&r,
e7f8ec2a 1580 st->setup_retries, st->setup_retry_interval,
3b83c932
SE
1581 send_msg, st);
1582
1583 if (r) {
ff05a229
SE
1584 st->state=next;
1585 if (next==SITE_RUN) {
1586 BUF_FREE(&st->buffer); /* Never reused */
1587 st->timeout=0; /* Never retransmit */
1588 activate_new_key(st);
1589 }
2fe58dfd
SE
1590 return True;
1591 }
ff05a229
SE
1592 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1593 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1594 in either state, and enter_state_wait() will
1595 do a BUF_FREE() */
2fe58dfd
SE
1596 enter_state_wait(st);
1597 return False;
1598}
1599
ff05a229 1600/* msg7 tells our peer that we're about to forget our key */
fe5e9cc4 1601static bool_t send_msg7(struct site *st, cstring_t reason)
794f2398 1602{
fe5e9cc4 1603 cstring_t transform_err;
794f2398 1604
3d8d8f4e 1605 if (current_valid(st) && st->buffer.free
446353cd 1606 && transport_peers_valid(&st->peers)) {
794f2398 1607 BUF_ALLOC(&st->buffer,"site:MSG7");
3abd18e8 1608 buffer_init(&st->buffer,calculate_max_start_pad());
794f2398
SE
1609 buf_append_uint32(&st->buffer,LABEL_MSG7);
1610 buf_append_string(&st->buffer,reason);
0afd257e
IJ
1611 if (call_transform_forwards(st, st->current.transform,
1612 &st->buffer, &transform_err))
1613 goto free_out;
794f2398 1614 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
58650a70 1615 buf_prepend_uint32(&st->buffer,st->index);
19e9a588 1616 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
446353cd 1617 transport_xmit(st,&st->peers,&st->buffer,True);
794f2398 1618 BUF_FREE(&st->buffer);
0afd257e 1619 free_out:
794f2398
SE
1620 return True;
1621 }
1622 return False;
1623}
1624
2fe58dfd
SE
1625/* We go into this state if our peer becomes uncommunicative. Similar to
1626 the "stop" state, we forget all session keys for a while, before
1627 re-entering the "run" state. */
1628static void enter_state_wait(struct site *st)
1629{
1630 slog(st,LOG_STATE,"entering state WAIT");
1631 st->timeout=st->now+st->wait_timeout;
1632 st->state=SITE_WAIT;
9d3a4132 1633 set_link_quality(st);
2fe58dfd
SE
1634 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1635 /* XXX Erase keys etc. */
1636}
1637
dd9209d1
IJ
1638static void generate_prod(struct site *st, struct buffer_if *buf)
1639{
1640 buffer_init(buf,0);
1641 buf_append_uint32(buf,0);
1642 buf_append_uint32(buf,0);
1643 buf_append_uint32(buf,LABEL_PROD);
1644 buf_append_string(buf,st->localname);
1645 buf_append_string(buf,st->remotename);
1646}
1647
1648static void generate_send_prod(struct site *st,
1649 const struct comm_addr *source)
1650{
1651 if (!st->allow_send_prod) return; /* too soon */
1652 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1653 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1654
1655 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1656 st->allow_send_prod=0;
1657 generate_prod(st,&st->scratch);
eff48c12 1658 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
62846523 1659 dump_packet(st,&st->scratch,source,False,ok);
dd9209d1
IJ
1660}
1661
16f73fa6 1662static inline void site_settimeout(uint64_t timeout, int *timeout_io)
fe5e9cc4
SE
1663{
1664 if (timeout) {
0009e60a
IJ
1665 int64_t offset=timeout-*now;
1666 if (offset<0) offset=0;
fe5e9cc4
SE
1667 if (offset>INT_MAX) offset=INT_MAX;
1668 if (*timeout_io<0 || offset<*timeout_io)
1669 *timeout_io=offset;
1670 }
1671}
1672
2fe58dfd 1673static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
90a39563 1674 int *timeout_io)
2fe58dfd
SE
1675{
1676 struct site *st=sst;
1677
ee697dd9 1678 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
2fe58dfd
SE
1679 st->now=*now;
1680
1681 /* Work out when our next timeout is. The earlier of 'timeout' or
19e9a588 1682 'current.key_timeout'. A stored value of '0' indicates no timeout
2fe58dfd 1683 active. */
16f73fa6 1684 site_settimeout(st->timeout, timeout_io);
19e9a588 1685 site_settimeout(st->current.key_timeout, timeout_io);
02b0959b 1686 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
2fe58dfd
SE
1687
1688 return 0; /* success */
1689}
1690
1d388569
IJ
1691static void check_expiry(struct site *st, struct data_key *key,
1692 const char *which)
1693{
1694 if (key->key_timeout && *now>key->key_timeout) {
1695 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1696 }
1697}
1698
2fe58dfd 1699/* NB site_afterpoll will be called before site_beforepoll is ever called */
90a39563 1700static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
2fe58dfd
SE
1701{
1702 struct site *st=sst;
1703
1704 st->now=*now;
1705 if (st->timeout && *now>st->timeout) {
2fe58dfd 1706 st->timeout=0;
3b83c932
SE
1707 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1708 if (!hacky_par_start_failnow())
1709 send_msg(st);
1710 } else if (st->state==SITE_WAIT) {
2fe58dfd
SE
1711 enter_state_run(st);
1712 } else {
1713 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1714 st->state);
1715 }
1716 }
1d388569 1717 check_expiry(st,&st->current,"current key");
02b0959b 1718 check_expiry(st,&st->auxiliary_key,"auxiliary key");
2fe58dfd
SE
1719}
1720
1721/* This function is called by the netlink device to deliver packets
1722 intended for the remote network. The packet is in "raw" wire
1723 format, but is guaranteed to be word-aligned. */
469fd1d9 1724static void site_outgoing(void *sst, struct buffer_if *buf)
2fe58dfd
SE
1725{
1726 struct site *st=sst;
fe5e9cc4 1727 cstring_t transform_err;
2fe58dfd
SE
1728
1729 if (st->state==SITE_STOP) {
1730 BUF_FREE(buf);
1731 return;
1732 }
1733
dd9209d1
IJ
1734 st->allow_send_prod=1;
1735
2fe58dfd
SE
1736 /* In all other states we consider delivering the packet if we have
1737 a valid key and a valid address to send it to. */
3d8d8f4e 1738 if (current_valid(st) && transport_peers_valid(&st->peers)) {
2fe58dfd 1739 /* Transform it and send it */
70dc107b
SE
1740 if (buf->size>0) {
1741 buf_prepend_uint32(buf,LABEL_MSG9);
0afd257e
IJ
1742 if (call_transform_forwards(st, st->current.transform,
1743 buf, &transform_err))
1744 goto free_out;
70dc107b 1745 buf_prepend_uint32(buf,LABEL_MSG0);
58650a70 1746 buf_prepend_uint32(buf,st->index);
19e9a588 1747 buf_prepend_uint32(buf,st->current.remote_session_id);
446353cd 1748 transport_xmit(st,&st->peers,buf,False);
70dc107b 1749 }
0afd257e 1750 free_out:
2fe58dfd
SE
1751 BUF_FREE(buf);
1752 return;
1753 }
1754
70dc107b 1755 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2fe58dfd 1756 BUF_FREE(buf);
dd9209d1 1757 initiate_key_setup(st,"outgoing packet",0);
2fe58dfd
SE
1758}
1759
7e29719e
IJ
1760static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1761 uint32_t type, struct msg *m)
1762 /* For packets which are identified by the local and remote names.
1763 * If it has our name and our peer's name in it it's for us. */
1764{
1765 struct buffer_if buf[1];
1766 buffer_readonly_clone(buf,buf_in);
1767 return unpick_msg(st,type,buf,m)
1768 && name_matches(&m->remote,st->remotename)
1769 && name_matches(&m->local,st->localname);
1770}
1771
67871f70 1772static bool_t we_have_priority(struct site *st, const struct msg *m) {
b2de6bd2
IJ
1773 if ((st->local_capabilities & m->remote_capabilities)
1774 && CAPAB_PRIORITY_MOBILE) {
1775 if (st->local_mobile) return True;
1776 if (st-> peer_mobile) return False;
1777 }
67871f70
IJ
1778 return st->our_name_later;
1779}
1780
db6534a3
IJ
1781static bool_t setup_late_msg_ok(struct site *st,
1782 const struct buffer_if *buf_in,
1783 uint32_t msgtype,
1784 const struct comm_addr *source) {
1785 /* For setup packets which seem from their type like they are
1786 * late. Maybe they came via a different path. All we do is make
1787 * a note of the sending address, iff they look like they are part
1788 * of the current key setup attempt. */
1789 struct msg m;
1790 if (!named_for_us(st,buf_in,msgtype,&m))
1791 /* named_for_us calls unpick_msg which gets the nonces */
1792 return False;
1793 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1794 !consttime_memeq(m.nL,st->localN, NONCELEN))
1795 /* spoof ? from stale run ? who knows */
1796 return False;
1797 transport_setup_msgok(st,source);
1798 return True;
1799}
1800
2fe58dfd 1801/* This function is called by the communication device to deliver
dd9209d1
IJ
1802 packets from our peers.
1803 It should return True if the packet is recognised as being for
1804 this current site instance (and should therefore not be processed
1805 by other sites), even if the packet was otherwise ignored. */
2fe58dfd 1806static bool_t site_incoming(void *sst, struct buffer_if *buf,
a15faeb2 1807 const struct comm_addr *source)
2fe58dfd
SE
1808{
1809 struct site *st=sst;
20138876
IJ
1810
1811 if (buf->size < 12) return False;
1812
0a6cbade
IJ
1813 uint32_t dest=get_uint32(buf->start);
1814 uint32_t msgtype=get_uint32(buf->start+8);
7e29719e
IJ
1815 struct msg named_msg;
1816
1817 if (msgtype==LABEL_MSG1) {
1818 if (!named_for_us(st,buf,msgtype,&named_msg))
1819 return False;
1820 /* It's a MSG1 addressed to us. Decide what to do about it. */
62846523 1821 dump_packet(st,buf,source,True,True);
7e29719e
IJ
1822 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1823 st->state==SITE_WAIT) {
1824 /* We should definitely process it */
45a14422 1825 transport_compute_setupinit_peers(st,0,0,source);
7e29719e
IJ
1826 if (process_msg1(st,buf,source,&named_msg)) {
1827 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
c22c3541 1828 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
83dbdd3f 1829 if (entered && st->addresses && st->local_mobile)
c22c3541
IJ
1830 /* We must do this as the very last thing, because
1831 the resolver callback might reenter us. */
1832 ensure_resolving(st);
7e29719e
IJ
1833 } else {
1834 slog(st,LOG_ERROR,"failed to process incoming msg1");
1835 }
1836 BUF_FREE(buf);
1837 return True;
1838 } else if (st->state==SITE_SENTMSG1) {
1839 /* We've just sent a message 1! They may have crossed on
1840 the wire. If we have priority then we ignore the
1841 incoming one, otherwise we process it as usual. */
67871f70 1842 if (we_have_priority(st,&named_msg)) {
7e29719e 1843 BUF_FREE(buf);
8b978d45 1844 if (!st->msg1_crossed_logged++)
dea92314 1845 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
8b978d45 1846 "priority => ignore incoming msg1");
7e29719e
IJ
1847 return True;
1848 } else {
dea92314 1849 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
7e29719e
IJ
1850 "priority => use incoming msg1");
1851 if (process_msg1(st,buf,source,&named_msg)) {
1852 BUF_FREE(&st->buffer); /* Free our old message 1 */
c22c3541 1853 transport_setup_msgok(st,source);
ff05a229 1854 enter_new_state(st,SITE_SENTMSG2);
2fe58dfd 1855 } else {
7e29719e
IJ
1856 slog(st,LOG_ERROR,"failed to process an incoming "
1857 "crossed msg1 (we have low priority)");
2fe58dfd
SE
1858 }
1859 BUF_FREE(buf);
1860 return True;
2fe58dfd 1861 }
04c5c5d7
IJ
1862 } else if (st->state==SITE_SENTMSG2 ||
1863 st->state==SITE_SENTMSG4) {
1864 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1865 /* We are ahead in the protocol, but that msg1 had the
1866 * peer's nonce so presumably it is from this key
1867 * exchange run, via a slower route */
1868 transport_setup_msgok(st,source);
1869 } else {
1870 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1871 }
1872 BUF_FREE(buf);
1873 return True;
2fe58dfd 1874 }
7e29719e 1875 /* The message 1 was received at an unexpected stage of the
04c5c5d7 1876 key setup. Well, they lost the race. */
7e29719e
IJ
1877 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1878 BUF_FREE(buf);
1879 return True;
2fe58dfd 1880 }
dd9209d1
IJ
1881 if (msgtype==LABEL_PROD) {
1882 if (!named_for_us(st,buf,msgtype,&named_msg))
1883 return False;
62846523 1884 dump_packet(st,buf,source,True,True);
dd9209d1
IJ
1885 if (st->state!=SITE_RUN) {
1886 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1887 } else if (current_valid(st)) {
1888 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1889 } else {
1890 initiate_key_setup(st,"peer sent PROD packet",source);
1891 }
1892 BUF_FREE(buf);
1893 return True;
1894 }
58650a70 1895 if (dest==st->index) {
2fe58dfd 1896 /* Explicitly addressed to us */
62846523 1897 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2fe58dfd 1898 switch (msgtype) {
136740e6 1899 case LABEL_NAK:
794f2398
SE
1900 /* If the source is our current peer then initiate a key setup,
1901 because our peer's forgotten the key */
19e9a588 1902 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
dd9209d1 1903 bool_t initiated;
e5e67212 1904 initiated = initiate_key_setup(st,"received a NAK",source);
dd9209d1 1905 if (!initiated) generate_send_prod(st,source);
794f2398
SE
1906 } else {
1907 slog(st,LOG_SEC,"bad incoming NAK");
1908 }
1909 break;
2fe58dfd
SE
1910 case LABEL_MSG0:
1911 process_msg0(st,buf,source);
1912 break;
1913 case LABEL_MSG1:
1914 /* Setup packet: should not have been explicitly addressed
1915 to us */
59635212 1916 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2fe58dfd
SE
1917 break;
1918 case LABEL_MSG2:
1919 /* Setup packet: expected only in state SENTMSG1 */
1920 if (st->state!=SITE_SENTMSG1) {
db6534a3
IJ
1921 if ((st->state==SITE_SENTMSG3 ||
1922 st->state==SITE_SENTMSG5) &&
1923 setup_late_msg_ok(st,buf,msgtype,source))
1924 break;
2fe58dfd 1925 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
446353cd
IJ
1926 } else if (process_msg2(st,buf,source)) {
1927 transport_setup_msgok(st,source);
ff05a229 1928 enter_new_state(st,SITE_SENTMSG3);
446353cd 1929 } else {
59635212 1930 slog(st,LOG_SEC,"invalid MSG2");
2fe58dfd
SE
1931 }
1932 break;
1933 case LABEL_MSG3:
5b5f297f 1934 case LABEL_MSG3BIS:
2fe58dfd
SE
1935 /* Setup packet: expected only in state SENTMSG2 */
1936 if (st->state!=SITE_SENTMSG2) {
db6534a3
IJ
1937 if ((st->state==SITE_SENTMSG4) &&
1938 setup_late_msg_ok(st,buf,msgtype,source))
1939 break;
2fe58dfd 1940 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
5b5f297f 1941 } else if (process_msg3(st,buf,source,msgtype)) {
446353cd 1942 transport_setup_msgok(st,source);
ff05a229 1943 enter_new_state(st,SITE_SENTMSG4);
446353cd 1944 } else {
59635212 1945 slog(st,LOG_SEC,"invalid MSG3");
2fe58dfd
SE
1946 }
1947 break;
1948 case LABEL_MSG4:
1949 /* Setup packet: expected only in state SENTMSG3 */
1950 if (st->state!=SITE_SENTMSG3) {
db6534a3
IJ
1951 if ((st->state==SITE_SENTMSG5) &&
1952 setup_late_msg_ok(st,buf,msgtype,source))
1953 break;
2fe58dfd 1954 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
446353cd
IJ
1955 } else if (process_msg4(st,buf,source)) {
1956 transport_setup_msgok(st,source);
ff05a229 1957 enter_new_state(st,SITE_SENTMSG5);
446353cd 1958 } else {
59635212 1959 slog(st,LOG_SEC,"invalid MSG4");
2fe58dfd
SE
1960 }
1961 break;
1962 case LABEL_MSG5:
4efd681a
SE
1963 /* Setup packet: expected only in state SENTMSG4 */
1964 /* (may turn up in state RUN if our return MSG6 was lost
1965 and the new key has already been activated. In that
05f39b4d
IJ
1966 case we discard it. The peer will realise that we
1967 are using the new key when they see our data packets.
1968 Until then the peer's data packets to us get discarded. */
c90cc2a7
IJ
1969 if (st->state==SITE_SENTMSG4) {
1970 if (process_msg5(st,buf,source,st->new_transform)) {
1971 transport_setup_msgok(st,source);
1972 enter_new_state(st,SITE_RUN);
1973 } else {
1974 slog(st,LOG_SEC,"invalid MSG5");
1975 }
1976 } else if (st->state==SITE_RUN) {
19e9a588 1977 if (process_msg5(st,buf,source,st->current.transform)) {
c90cc2a7
IJ
1978 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1979 transport_setup_msgok(st,source);
19e9a588
IJ
1980 create_msg6(st,st->current.transform,
1981 st->current.remote_session_id);
c90cc2a7
IJ
1982 transport_xmit(st,&st->peers,&st->buffer,True);
1983 BUF_FREE(&st->buffer);
1984 } else {
1985 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1986 }
2fe58dfd 1987 } else {
c90cc2a7 1988 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2fe58dfd
SE
1989 }
1990 break;
1991 case LABEL_MSG6:
1992 /* Setup packet: expected only in state SENTMSG5 */
1993 if (st->state!=SITE_SENTMSG5) {
1994 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1995 } else if (process_msg6(st,buf,source)) {
1996 BUF_FREE(&st->buffer); /* Free message 5 */
446353cd 1997 transport_setup_msgok(st,source);
2fe58dfd
SE
1998 activate_new_key(st);
1999 } else {
59635212 2000 slog(st,LOG_SEC,"invalid MSG6");
2fe58dfd
SE
2001 }
2002 break;
2fe58dfd 2003 default:
59635212 2004 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2fe58dfd
SE
2005 msgtype);
2006 break;
2007 }
2008 BUF_FREE(buf);
2009 return True;
2010 }
2011
2012 return False;
2013}
2014
2015static void site_control(void *vst, bool_t run)
2016{
2017 struct site *st=vst;
2018 if (run) enter_state_run(st);
2019 else enter_state_stop(st);
2020}
2021
794f2398
SE
2022static void site_phase_hook(void *sst, uint32_t newphase)
2023{
2024 struct site *st=sst;
2025
2026 /* The program is shutting down; tell our peer */
2027 send_msg7(st,"shutting down");
2028}
2029
32654a31
IJ
2030static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2031{
2032 struct site *st=sst;
2033 dispose_transform(&st->current.transform);
2034 dispose_transform(&st->auxiliary_key.transform);
2035 dispose_transform(&st->new_transform);
2036 /* Not much point overwiting the signing key, since we loaded it
2037 from disk, and it is only valid prospectively if at all,
2038 anyway. */
2039 /* XXX it would be best to overwrite the DH state, because that
2040 _is_ relevant to forward secrecy. However we have no
2041 convenient interface for doing that and in practice gmp has
2042 probably dribbled droppings all over the malloc arena. A good
2043 way to fix this would be to have a privsep child for asymmetric
2044 crypto operations, but that's a task for another day. */
2045}
2046
2fe58dfd
SE
2047static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2048 list_t *args)
2049{
58650a70 2050 static uint32_t index_sequence;
2fe58dfd
SE
2051 struct site *st;
2052 item_t *item;
2053 dict_t *dict;
59533c16 2054 int i;
2fe58dfd 2055
b7886fd4 2056 NEW(st);
2fe58dfd
SE
2057
2058 st->cl.description="site";
2059 st->cl.type=CL_SITE;
2060 st->cl.apply=NULL;
2061 st->cl.interface=&st->ops;
2062 st->ops.st=st;
2063 st->ops.control=site_control;
2064 st->ops.status=site_status;
2065
2066 /* First parameter must be a dict */
2067 item=list_elem(args,0);
2068 if (!item || item->type!=t_dict)
2069 cfgfatal(loc,"site","parameter must be a dictionary\n");
2070
2071 dict=item->data.dict;
558fa3fb
SE
2072 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2073 st->remotename=dict_read_string(dict, "name", True, "site", loc);
dba19f84 2074
e6d6991c
IJ
2075 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2076
dba19f84 2077 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
0391d9ee 2078 st->local_mobile=
dba19f84
IJ
2079 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2080
558fa3fb
SE
2081 /* Sanity check (which also allows the 'sites' file to include
2082 site() closures for all sites including our own): refuse to
2083 talk to ourselves */
2084 if (strcmp(st->localname,st->remotename)==0) {
b2a56f7c 2085 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
baa06aeb 2086 st->localname);
0391d9ee 2087 if (st->peer_mobile != st->local_mobile)
dba19f84
IJ
2088 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2089 " but our local-mobile=%d\n",
0391d9ee 2090 st->localname, st->peer_mobile, st->local_mobile);
dba19f84
IJ
2091 free(st);
2092 return NULL;
2093 }
0391d9ee 2094 if (st->peer_mobile && st->local_mobile) {
dba19f84
IJ
2095 Message(M_WARNING,"site %s: site is mobile but so are we"
2096 " -> ignoring this site\n", st->remotename);
558fa3fb
SE
2097 free(st);
2098 return NULL;
2099 }
dba19f84 2100
58650a70
RK
2101 assert(index_sequence < 0xffffffffUL);
2102 st->index = ++index_sequence;
09a385fb 2103 st->local_capabilities = 0;
469fd1d9 2104 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
59533c16 2105
5b5f297f
IJ
2106#define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2107 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2108 if (!things##_cfg) \
2109 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2110 st->nthings=list_length(things##_cfg); \
b4ececfc 2111 NEW_ARY(st->things,st->nthings); \
5b5f297f
IJ
2112 assert(st->nthings); \
2113 for (i=0; i<st->nthings; i++) { \
2114 item_t *item=list_elem(things##_cfg,i); \
2115 if (item->type!=t_closure) \
2116 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2117 closure_t *cl=item->data.closure; \
2118 if (cl->type!=CL_TYPE) \
2119 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2120 st->things[i]=cl->interface; \
2121 } \
2122}while(0)
2123
2124 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
59533c16 2125
5dfe538b
IJ
2126 NEW_ARY(st->commclientinfos, st->ncomms);
2127 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2128 for (i=0; i<st->ncomms; i++) {
2129 st->commclientinfos[i] =
2130 !comminfo ? 0 :
2131 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2132 }
2133
2fe58dfd
SE
2134 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2135 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2136 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2137
2fe58dfd 2138 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
83dbdd3f
IJ
2139 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2140 if (st->addresses)
3454dce4
SE
2141 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2142 else st->remoteport=0;
2fe58dfd
SE
2143 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
2144
5b5f297f 2145 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2fe58dfd
SE
2146
2147 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2148 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2149
0391d9ee 2150#define DEFAULT(D) (st->peer_mobile || st->local_mobile \
e57264d6 2151 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
e7f8ec2a 2152#define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
c27ca22f 2153
e7f8ec2a
IJ
2154 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2155 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2156 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2157 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
3ed1846a 2158 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
e7f8ec2a 2159
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2160 st->mobile_peer_expiry= dict_read_number(
2161 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2162
0f27325c
IJ
2163 const char *peerskey= st->peer_mobile
2164 ? "mobile-peers-max" : "static-peers-max";
2165 st->transport_peers_max= dict_read_number(
83dbdd3f 2166 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
446353cd 2167 if (st->transport_peers_max<1 ||
0f27325c
IJ
2168 st->transport_peers_max>MAX_PEER_ADDRS) {
2169 cfgfatal(loc,"site", "%s must be in range 1.."
2170 STRING(MAX_PEER_ADDRS) "\n", peerskey);
446353cd
IJ
2171 }
2172
e7f8ec2a 2173 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
c27ca22f
IJ
2174 st->key_renegotiate_time=st->key_lifetime/2;
2175 else
e7f8ec2a 2176 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
9d3a4132 2177 st->key_renegotiate_time=dict_read_number(
cce0051f 2178 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
9d3a4132
SE
2179 if (st->key_renegotiate_time > st->key_lifetime) {
2180 cfgfatal(loc,"site",
2181 "renegotiate-time must be less than key-lifetime\n");
2182 }
9d3a4132
SE
2183
2184 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2185 log_event_table,"site");
2fe58dfd 2186
83dbdd3f 2187 st->resolving_count=0;
dd9209d1
IJ
2188 st->allow_send_prod=0;
2189
4efd681a
SE
2190 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2191 "site_apply");
2192 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2193
2fe58dfd 2194 /* The information we expect to see in incoming messages of type 1 */
59230b9b
IJ
2195 /* fixme: lots of unchecked overflows here, but the results are only
2196 corrupted packets rather than undefined behaviour */
ffafab08 2197 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2fe58dfd
SE
2198
2199 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2200
8aaaa634 2201 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
05f39b4d
IJ
2202 BUF_ALLOC(&st->scratch,"site:scratch");
2203
2fe58dfd
SE
2204 /* We are interested in poll(), but only for timeouts. We don't have
2205 any fds of our own. */
32fc582f 2206 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2fe58dfd
SE
2207 st->timeout=0;
2208
09a385fb 2209 st->remote_capabilities=0;
5b5f297f 2210 st->chosen_transform=0;
19e9a588 2211 st->current.key_timeout=0;
02b0959b 2212 st->auxiliary_key.key_timeout=0;
446353cd
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2213 transport_peers_clear(st,&st->peers);
2214 transport_peers_clear(st,&st->setup_peers);
2fe58dfd
SE
2215 /* XXX mlock these */
2216 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
5b5f297f
IJ
2217 st->sharedsecretlen=st->sharedsecretallocd=0;
2218 st->sharedsecret=0;
2219
5b5f297f
IJ
2220 for (i=0; i<st->ntransforms; i++) {
2221 struct transform_if *ti=st->transforms[i];
2222 uint32_t capbit = 1UL << ti->capab_transformnum;
2223 if (st->local_capabilities & capbit)
2224 slog(st,LOG_ERROR,"transformnum capability bit"
2225 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
2226 st->local_capabilities |= capbit;
59533c16 2227 }
59533c16 2228
b2de6bd2
IJ
2229 if (st->local_mobile || st->peer_mobile)
2230 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2231
2fe58dfd 2232 /* We need to register the remote networks with the netlink device */
3ed1846a
IJ
2233 uint32_t netlink_mtu; /* local virtual interface mtu */
2234 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2235 if (!st->mtu_target)
2236 st->mtu_target=netlink_mtu;
ff05a229 2237
59533c16
IJ
2238 for (i=0; i<st->ncomms; i++)
2239 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2fe58dfd 2240
fcad4b0b
IJ
2241 st->current.transform=0;
2242 st->auxiliary_key.transform=0;
2243 st->new_transform=0;
bd98cd6b 2244 st->auxiliary_is_new=0;
2fe58dfd
SE
2245
2246 enter_state_stop(st);
2247
794f2398 2248 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
32654a31 2249 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
794f2398 2250
2fe58dfd
SE
2251 return new_closure(&st->cl);
2252}
2253
2fe58dfd
SE
2254void site_module(dict_t *dict)
2255{
2256 add_closure(dict,"site",site_apply);
2257}
446353cd
IJ
2258
2259
2260/***** TRANSPORT PEERS definitions *****/
2261
2262static void transport_peers_debug(struct site *st, transport_peers *dst,
2263 const char *didwhat,
2264 int nargs, const struct comm_addr *args,
2265 size_t stride) {
2266 int i;
2267 char *argp;
2268
2269 if (!(st->log_events & LOG_PEER_ADDRS))
2270 return; /* an optimisation */
2271
2272 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2273 (dst==&st->peers ? "data" :
2274 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2275 didwhat, nargs, dst->npeers);
2276
2277 for (i=0, argp=(void*)args;
2278 i<nargs;
2279 i++, (argp+=stride?stride:sizeof(*args))) {
2280 const struct comm_addr *ca=(void*)argp;
2281 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1a448682 2282 i, comm_addr_to_string(ca));
446353cd
IJ
2283 }
2284 for (i=0; i<dst->npeers; i++) {
2285 struct timeval diff;
2286 timersub(tv_now,&dst->peers[i].last,&diff);
2287 const struct comm_addr *ca=&dst->peers[i].addr;
2288 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1a448682 2289 i, comm_addr_to_string(ca),
446353cd
IJ
2290 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2291 }
2292}
2293
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IJ
2294static void transport_peers_expire(struct site *st, transport_peers *peers) {
2295 /* peers must be sorted first */
2296 int previous_peers=peers->npeers;
2297 struct timeval oldest;
2298 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2299 oldest.tv_usec = tv_now->tv_usec;
2300 while (peers->npeers>1 &&
2301 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2302 peers->npeers--;
2303 if (peers->npeers != previous_peers)
2304 transport_peers_debug(st,peers,"expire", 0,0,0);
2305}
2306
51fc5a74
IJ
2307static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2308 const struct comm_addr *ca,
2309 const struct timeval *tv) {
2310 /* returns false if output is full */
2311 int search;
446353cd 2312
51fc5a74
IJ
2313 if (peers->npeers >= st->transport_peers_max)
2314 return 0;
446353cd 2315
51fc5a74 2316 for (search=0; search<peers->npeers; search++)
2093fb5c 2317 if (comm_addr_equal(&peers->peers[search].addr, ca))
51fc5a74
IJ
2318 return 1;
2319
2320 peers->peers[peers->npeers].addr = *ca;
2321 peers->peers[peers->npeers].last = *tv;
2322 peers->npeers++;
2323 return 1;
2324}
2325
2326static void transport_record_peers(struct site *st, transport_peers *peers,
2327 const struct comm_addr *addrs, int naddrs,
2328 const char *m) {
2329 /* We add addrs into peers. The new entries end up at the front
2330 * and displace entries towards the end (perhaps even off the
2331 * end). Any existing matching entries are moved up to the front.
2332 *
2333 * Caller must first call transport_peers_expire. */
2334
fdef47ec
IJ
2335 if (naddrs==1) {
2336 /* avoids debug for uninteresting updates */
2337 int i;
2338 for (i=0; i<peers->npeers; i++) {
2339 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2340 memmove(peers->peers+1, peers->peers,
2341 sizeof(peers->peers[0]) * i);
2342 peers->peers[0].addr = addrs[0];
2343 peers->peers[0].last = *tv_now;
2344 return;
2345 }
2346 }
51fc5a74 2347 }
446353cd 2348
51fc5a74
IJ
2349 int old_npeers=peers->npeers;
2350 transport_peer old_peers[old_npeers];
2351 COPY_ARRAY(old_peers,peers->peers,old_npeers);
446353cd 2352
51fc5a74
IJ
2353 peers->npeers=0;
2354 int i;
2355 for (i=0; i<naddrs; i++) {
2356 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2357 break;
2358 }
2359 for (i=0; i<old_npeers; i++) {
2360 const transport_peer *old=&old_peers[i];
2361 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2362 break;
2363 }
446353cd 2364
51fc5a74
IJ
2365 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2366}
2367
2368static void transport_expire_record_peers(struct site *st,
2369 transport_peers *peers,
2370 const struct comm_addr *addrs,
2371 int naddrs, const char *m) {
2372 /* Convenience function */
2373 transport_peers_expire(st,peers);
2374 transport_record_peers(st,peers,addrs,naddrs,m);
446353cd
IJ
2375}
2376
2377static bool_t transport_compute_setupinit_peers(struct site *st,
45a14422
IJ
2378 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2379 int n_configured_addrs /* 0 if none or not found */,
a96fda35 2380 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
45a14422 2381 if (!n_configured_addrs && !incoming_packet_addr &&
dd9209d1 2382 !transport_peers_valid(&st->peers))
446353cd
IJ
2383 return False;
2384
2385 slog(st,LOG_SETUP_INIT,
45a14422
IJ
2386 "using: %d configured addr(s);%s %d old peer addrs(es)",
2387 n_configured_addrs,
a96fda35 2388 incoming_packet_addr ? " incoming packet address;" : "",
779837e1 2389 st->peers.npeers);
446353cd 2390
0f27325c
IJ
2391 /* Non-mobile peers try addresses until one is plausible. The
2392 * effect is that this code always tries first the configured
2393 * address if supplied, or otherwise the address of the incoming
2394 * PROD, or finally the existing data peer if one exists; this is
2395 * as desired. */
446353cd
IJ
2396
2397 transport_peers_copy(st,&st->setup_peers,&st->peers);
51fc5a74 2398 transport_peers_expire(st,&st->setup_peers);
446353cd 2399
a96fda35 2400 if (incoming_packet_addr)
51fc5a74
IJ
2401 transport_record_peers(st,&st->setup_peers,
2402 incoming_packet_addr,1, "incoming");
dd9209d1 2403
45a14422 2404 if (n_configured_addrs)
51fc5a74 2405 transport_record_peers(st,&st->setup_peers,
45a14422 2406 configured_addrs,n_configured_addrs, "setupinit");
446353cd
IJ
2407
2408 assert(transport_peers_valid(&st->setup_peers));
2409 return True;
2410}
2411
2412static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2413 if (st->peer_mobile)
51fc5a74 2414 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
446353cd
IJ
2415}
2416static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2417 if (st->peer_mobile)
51fc5a74 2418 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
446353cd
IJ
2419}
2420
2421static int transport_peers_valid(transport_peers *peers) {
2422 return peers->npeers;
2423}
2424static void transport_peers_clear(struct site *st, transport_peers *peers) {
2425 peers->npeers= 0;
2426 transport_peers_debug(st,peers,"clear",0,0,0);
2427}
2428static void transport_peers_copy(struct site *st, transport_peers *dst,
2429 const transport_peers *src) {
2430 dst->npeers=src->npeers;
4f28e77e 2431 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
446353cd 2432 transport_peers_debug(st,dst,"copy",
a620a048 2433 src->npeers, &src->peers->addr, sizeof(*src->peers));
446353cd
IJ
2434}
2435
90d7e3ad 2436static void transport_resolve_complete(struct site *st,
45a14422
IJ
2437 const struct comm_addr *addrs,
2438 int naddrs) {
2439 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2440 "resolved data");
2441 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2442 "resolved setup");
90d7e3ad
IJ
2443}
2444
2445static void transport_resolve_complete_tardy(struct site *st,
45a14422
IJ
2446 const struct comm_addr *addrs,
2447 int naddrs) {
2448 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2449 "resolved tardily");
90d7e3ad
IJ
2450}
2451
027a218f
IJ
2452static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2453 unsigned mask,
2454 const transport_peers *inp) {
2455 /* out and in->peers may be the same region, or nonoverlapping */
2456 const transport_peer *in=inp->peers;
2457 int slot;
2458 for (slot=0; slot<inp->npeers; slot++) {
2459 if (!(mask & (1U << slot)))
2460 continue;
2461 if (!(out==in && slot==*nout_io))
2462 COPY_OBJ(out[*nout_io], in[slot]);
2463 (*nout_io)++;
2464 }
2465}
2466
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2467void transport_xmit(struct site *st, transport_peers *peers,
2468 struct buffer_if *buf, bool_t candebug) {
2469 int slot;
2470 transport_peers_expire(st, peers);
027a218f 2471 unsigned failed=0; /* bitmask */
0f27325c 2472 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
027a218f
IJ
2473
2474 int nfailed=0;
446353cd
IJ
2475 for (slot=0; slot<peers->npeers; slot++) {
2476 transport_peer *peer=&peers->peers[slot];
eff48c12 2477 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
62846523
IJ
2478 if (candebug)
2479 dump_packet(st, buf, &peer->addr, False, ok);
027a218f
IJ
2480 if (!ok) {
2481 failed |= 1U << slot;
2482 nfailed++;
2483 }
2484 if (ok && !st->peer_mobile)
2485 break;
2486 }
2487 /* Now we need to demote/delete failing addrs: if we are mobile we
2488 * merely demote them; otherwise we delete them. */
2489 if (st->local_mobile) {
2490 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2491 /* `expected' has all the failures at the end already */
2492 if (failed != expected) {
2493 int fslot=0;
2494 transport_peer failedpeers[nfailed];
2495 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2496 assert(fslot == nfailed);
2497 int wslot=0;
2498 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2499 assert(wslot+nfailed == peers->npeers);
2500 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
92ae57c5 2501 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
027a218f
IJ
2502 }
2503 } else {
2504 if (failed && peers->npeers > 1) {
2505 int wslot=0;
2506 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2507 peers->npeers=wslot;
92ae57c5 2508 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
027a218f 2509 }
446353cd
IJ
2510 }
2511}
2512
2513/***** END of transport peers declarations *****/